Evaluation of Reservoir Fluids Mobility, Mauddud Reservoir (Albian), Khabbaz Oil Field, Kirkuk Area, NE Iraq

Abstract

The Albian Mauddud reservoir of the Khabbaz Oil Field is consisting of 170 m alternating shelf carbonates and pervasive dolomite horizons of coarse to fine crystalline mosaic. Core analysis and log measurements reveal the occurrence of three electrofacies units (A, B, and C) with variable petrophysical properties. Unit A with good reservoir quality shows average porosity of 18.8 % and average permeability of 27.5 md. The other two units (B and C) are less attractive and have an average porosity of 9.6 % and 9.2 % consequently. Pore size ranges between macro to meso types and related mainly to vugs, fractures and intercrystalline porosity, especially in the dolomite units. The reservoir fluids saturation, bulk volume, and mobility are evaluated using resistivity logs measurements and porosity logs (Neutron-Density porosities) in addition to other reservoir laboratory data. Calculations and cross data plotting of the related petrophysical parameters were applied to the three units of the Mauddud reservoir in seven wells of the field. It shows an overall good reservoir fluids mobility. Results indicate that the formation water of Khabbaz Oil Feld is a non-movable type especially for the crestal wells which make most of these wells produce water-free hydrocarbon. Variability within well’s hydrocarbon mobility is noticed and related to units and subunits lithology and porosity variation. Other variations seem to be related mainly to permeability, pores geometry and variability of water saturation in addition to the location of well with respect to oil pool within the field structure.

Reworked Mesozoic Radiolarians in Miocene-Pliocene Foreland Sediments in the Zagros Belt, Iran

“…Enhanced erosion of radiolarians from these softer low-diversity radiolarian claystones compared to interbedded harder radiolarian cherts or limestones is therefore possibly a prime factor accounting for the high percentage of cryptothoracic nassellarians observed in this study, while other radiolarian taxa described from radiolarites Gharib and De Wever (2010) and Al-Qayim et al (2018) are missing. The RRCU with a thickness of 80-100 m has only been analysed by a single sediment sample so far (KN-32), therefore the age span covered given by Al-Qayim et al (2018) might possibly be too short. This might explain the missing age range overlap between the RRCU and some of the cryptothoracical taxa observed in this study such as Cryptamphorella conara (Foreman) (Fig.…”

“…The Zagros radiolarites found within the Imbricate Zagros have been described in the literature as Qulqula radiolarites in Iraq and Kermanshah radiolarites in Iran. They have been micropaleontologically constrained to the lower Pliensbachian up to the Turonian at Kermanshah, Iran (Gharib & De Wever 2010) and Bajocian to the end of the Cenomanian at Qulqula, Iraq (Al-Qayim et al 2018). Reworked radiolarians identified in this study in the Zagros foreland sediments are generally of Cretaceous age while Jurassic ones are poorly represented.…”

“…Holocryptocanium barbui (Dumitrica) is the most commonly observed taxon in this study. In the Qulqula -Kermanshah radiolarites H. barbui (Dumitrica) has so been observed in the RRCU (Al-Qayim et al 2018), where it has been reported alongside Archaeodictyomitra mitra (Dumitrica), Angulobracchia portmanni s.l. (Baumgartner) and Pseudodictyomitra carpatica (Lozyinak).…”

“…Deformation intensity is decreasing from the Zagros Suture Zone to the present deformation front, located near the Iran-Iraq border (Alavi 1994;Berberian 1995). The ZFTB belt is tectonically divided, from the SW to the NE, into four zones; (1) the Mesopotamian Fo-reland Basin with buried folds, extending into the Persian Gulf, (2) the Folded Belt characterized by simple folds, (3) the Imbricated Zone characterized by thrusting, including ophiolite sequences with radiolarites of Jurassic to Cretaceous age (Gharib & De Wever 2010;Al-Qayim et al 2018); and (4) the Sanandaj-Sirjan metamorphic and magmatic zone (Homke et al 2004;. The Zagros foreland sediments were, next to an aeolian contribution (Böhme et al 2021), largely deposited by axial and radial fluvial systems in the Miocene and alluvial fan systems in the Pliocene, derived from the Zagros mountain belt (Koshnaw et al 2020).…”

“…(Baumgartner) and Pseudodictyomitra carpatica (Lozyinak). The radiolarian claystones of the RRCU are of Berriasian to early Aptian age (Al-Qayim et al 2018). They possibly represent the "Crypto-Archaeo" Assemblage, comprising low diversity, ecologically tolerant forms (chiefly cryptocephalic and cryptothoracic nassellarians and Archeodictyomitra spp.)…”